A process automation system refers to a monitoring and control system, usually of an industrial system or a set of industrial processes, in which a distributed control system (DCS) may utilize controller elements to monitor and control the industrial processes. With regard to monitoring, the industrial processes generate process data that is transmitted to the DCS, often in real time. The DCS subsequently displays the process data for human operators that monitor and control the industrial process via an operator console. The components of the process automation system may be connected by a process control communications network.
For purposes of troubleshooting malfunctions and optimizing performance, it is common practice to store process data of the process automation system for later analysis. One of the current approaches to data storage of process data for process automation systems includes commercial relational databases. This approach, however, is associated with significant storage and processing overhead when dealing with real time data. Further, data query times of real time data in a relational database are lengthy, and can make the system impractical to use.
Another known approach to data storage of process data for process automation systems includes commercial data historians. A data historian is a computer process including storage that automatically captures and logs information from disparate data sources, usually from industrial systems. Although more efficient than relational databases in terms of storage space, the storage mechanisms of data historians are not flexible and have consequent drawbacks. Analysis of stored data, for example, often entails rebuilding the original data stream from the stored data and then executing the desired analysis processes. This stepwise approach to analysis can cause unwanted delays in processing and displaying data when dealing with data collected over long periods of time. In addition, the storage mechanisms of data historians require complex data types to be stored as single binary files, which increases the processing burden when analyzing the complex data types at a later time.
Another known approach to data storage of process data for process automation systems includes custom programmed systems. Although this approach provides custom process control and engineering experience to the process automation system, the drawbacks of this approach include the inability to offer transparency of data and the requirement of custom interfaces to transfer data into other systems or reports, thereby making this approach unattractive to certain users. Therefore, there is a need for a more efficient method and system for storing process data for process automation systems.